Slow wave sleep disruption increases cerebrospinal fluid amyloid-β levels

Yo-El S Ju1,2, Sharon J Ooms3,4,5, Courtney Sutphen1,2

  • 1Department of Neurology, Washington University, Saint Louis, Missouri, USA.

Insights

Disrupting slow wave sleep acutely raises amyloid-beta levels. Additionally, poor sleep quality over days is linked to increased tau, suggesting sleep impacts Alzheimer's disease biomarkers.

Area of Science:

  • Neuroscience
  • Sleep Medicine
  • Biomarkers of Alzheimer's Disease

Background:

  • Chronic sleep disruption is implicated in Alzheimer's disease (AD) pathologies, including amyloid-beta (Aβ) plaque formation.
  • Previous research suggests a link between sleep deprivation and increased Aβ, but specific sleep aspects modulating AD biomarkers remain unclear.

Purpose of the Study:

  • To investigate the impact of specific sleep disruptions on key Alzheimer's disease biomarkers.
  • To determine whether acute disruption of slow-wave activity or chronic poor sleep quality affects Aβ and tau levels.

Main Methods:

  • Seventeen healthy adults (35-65 years) underwent actigraphy for sleep monitoring.
  • Polysomnography was used to disrupt slow-wave activity, followed by cerebrospinal fluid collection.
  • Cerebrospinal fluid biomarkers including Aβ40, tau, and YKL-40 were measured and compared to a sham condition.

Main Results:

  • Acute disruption of slow-wave activity specifically increased amyloid-beta40 levels (r = 0.610, P = 0.009).
  • This effect was independent of sleep duration or efficiency and did not affect other measured proteins.
  • Poorer overnight sleep efficiency over several days was associated with higher tau levels (r = 0.543, P = 0.045).

Conclusions:

  • Acute slow-wave activity disruption elevates amyloid-beta levels, suggesting a direct impact on Aβ metabolism.
  • Chronic poor sleep quality, indicated by reduced sleep efficiency, is linked to increased tau.
  • These findings highlight the specific roles of different sleep characteristics in modulating neuronal protein biomarkers relevant to Alzheimer's disease.